When performing search queries of large corpora (e.g., the Internet), many irrelevant documents are often included in the search results because they contain all of the query terms. For example, a user searching for reviews of a particular model of camera may search for the name of the camera. In addition to the desired reviews, many online stores selling the camera may be returned, and these results may dominate the top of the result set. A conventional technique that users can apply to refine the search results is to add one or more terms to the query, such as the term “review.” Many online stores, however, allow shoppers to submit product reviews, so some of those documents may contain text, such as “Be the first to review this product,” making the refinement ineffective.